Comment On 'coexistence Of Bcs- And Bec-like Pair Structures In Halo Nuclei'

摘要

A recent Letter investigated the implication of the BCS-BEC crossover in finite neutron-rich nuclei. The point of view is that two-neutron halo nuclei like ~(11)Li, in spite of only one pair, provide optimum conditions to study BCS-and BEC-like features in finite nuclei. The procedure is to solve the three-body problem of two neutrons (coordinates r_1, r_2) outside the (~9Li-)core (coordinate r_c). The neutron-neutron interaction is called pairing interaction and the resulting structure is called pairing correlations. At small distances R, R = (r_1 + r_2)/2, the three-body wave function Ψ(r, R) exhibits oscillations as function of the neutron-neutron separation r, r = r_1 - r_2, and for large R this relative wave function resembles that of a bound state. This is the novel discovery claimed to arise from the neutron-neutron pairing interaction.